Development Of Desulphurizing Agent And Optimization Of Injection Technologic Paramenters For Hot Metal Of Chongqing Iron And Steel Co.

In this thesis, the compared experiment of desulphurization of hot metal of Chongqing Iron and Steel Co. (in short CQ), which is used by various desulphurizing agent, has been carried out in lab. On the base of the experiment, industrial experiment of selected three types, which is CaO-based, CaO-AD-based and CaO-Mg-based synthetic desulphurizing agent have been carried out; At one time, the injection technologic parameters have been optimized; The smelting resulfurization and smelting low-surphur steel in converter with the desulphurized hot metal have been researched in practice. Then the conclusions can be drawn as following: Through the experiments in lab and the thermodynamics analysis of the three types desulphurizing agent, which is CaO-based, CaO-AD-based and CaO-Mg-based desulphurizing agent, it can be gained that the array order of the desulphurization capacity from the stronger to the weaker is: CaO-Mg-based-CaO-AD-based -* CaO-based. It may be found from the industrial experiments at the steelworks in CQ.that the desulphurization effect of the three types desulphurizing agent which is contained CaO-based CaO-AD-based and CaO-Mg-based is better; The average desulphurization rate is between 70% and 80%. Especially; CaO-based desulphurizing agent can also achieve a high desulphurization rate after used the high quality components. Judging from the consumption, treating time and the temperature drop of the powder agent, the array order of the three types of desulphurizing agent from the worse to the better is: CaO-based-CaO-AD-based -CaO-Mg-based. Through orthogonal experiment measure, it can be obtained that the scrap quality is the chiefly factor to affect resulfurization of the desulphurized hot metal in the converter at the steelworks in CQ; The second factor is decided by the slag removal which is better or not; The last factor is decided by lime quality.The best production scheme of low-surphur steel,which can ensure lowest the resulfurization quantity, is: the high quality of slag removal-low-surphur scrap-gas burned low-surphur lime.(5) In the condition of the schemes for the lowest resulfurization quantity, the low-surphur steel experiments can prove that the steelworks in CQ. has the capacity of producing the low-surphur steel for the sulfur content less than 0.015% of the finished products.